Cooling apparatuses including an evaporator and a condenser, and a vapor tube and liquid tube connected to the evaporator and the condenser, have existed hitherto. In such cooling apparatuses, when a coolant inside the evaporator is vaporized by the heat of a heat generating body so as to generate vapor in the evaporator, the vapor is conveyed from the evaporator to the condenser through the vapor tube. In the condenser, the vapor conveyed through the vapor tube is liquefied, and the liquefied coolant in the condenser is returned from the condenser to the evaporator through the liquid tube. By circulating the coolant between the evaporator and the condenser as described above, the heat of the heat generating body is transported from the evaporator to the condenser by the coolant, thereby cooling the heat generating body.
This type of cooling apparatus includes cooling apparatuses in which a valve is provided to at least the vapor tube out of the vapor tube and the liquid tube. As an example of such a cooling apparatus provided with a valve, a cooling apparatus exists in which a valve is actuated according to a pressure difference between the interior and exterior of a circulation path around which the coolant circulates in order to regulate the coolant circulation rate, with the purpose of preventing the inside of the evaporator from drying out accompanying freezing of the liquid tube.
As another example of such a cooling apparatus provided with a valve, a cooling apparatus exists in which a valve is actuated according to the surface temperature of the evaporator in order to regulate the coolant circulation rate, with the purpose of preventing the inside of the evaporator from drying out accompanying a sudden rise in the temperature of the evaporator.